| 摘要 |
An apparatus for improving the link margin of a communication link includes a variable rate vocoder which decreases the output bit stream rate it produces so as to reduce the amount of information having to be transmit in the communication link. In one embodiment, the variable rate vocoder includes a plurality of vocoder portions, each of which produces a different bit stream rate. The selector is used for selecting among the output bit streams produced by each vocoder. In another embodiment, a logic device is coupled to the output of the vocoder. The logic device, upon receipt of a control signal, truncates the less important bits. The method for improving link margin includes reducing the vocoder output rate thereby reducing the amount of data being transmit in an communication link. The method also includes using increased error correction coding and transmitting at increased per bit power levels to increase link margin. A device knows to increase the link margin whenever it receives a request to do so, which request is based upon poor signal quality.
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